verapamil hydrochloride

Drug Name

Generic Name :  verapamil hydrochloride

Brand Name: Apo-Verapamil (CAN), Calan, Calan SR, Covera-HS, Gen-Verapamil (CAN), Gen-Verapamil SR (CAN), Isoptin SR, Novo-Verapamil SR (CAN), Nu-Verap (CAN), Verelan, Verelan PM

Classification: Calcium channel-blocker, Antianginal, Antiarrhythmic, Antihypertensive

Pregnancy Category C 

Dosage & Route
ADULTS

Oral

Immediate release

  • Angina: 80 mg q 6–8 hr; may increase by 80 mg at weekly intervals until control is achieved. Maintenance 240–480 mg daily.
  • Arrhythmias: 240–480 mg/day.
  • In digitalized adults: 240–320 mg/day.
  • Hypertension: 40 mg to 80 mg PO tid.

ER

  • Capsules: 120–240 mg/day PO in the morning. Titrate dose to a maximum 480 mg/day.
  • Tablets: 120–180 mg/day PO in the morning. Titrate to a maximum 240 mg q 12 hr.

SR

  • 120–180 mg/day PO. Titrate up to a maximum 480 mg PO in the morning.

Parenteral

  • IV use only. Initial dose, 2.5–10 mg over 2 min; may repeat dose of 10 mg 30 min after first dose if initial response is inadequate.
PEDIATRIC PATIENTS

IV

  • < 1 yr: Initial dose, 0.1–0.2 mg/kg over 2 min.
  • 1–15 yr: Initial dose, 0.1–0.3 mg/kg over 2 min. Do not exceed 5 mg. Repeat above dose 30 min after initial dose if response is not adequate. Repeat dose should not exceed 10 mg.
GERIATRIC PATIENTS OR PATIENTS WITH RENAL IMPAIRMENT
  • Reduce dosage, and monitor patient response carefully. Give IV doses over 3 min to reduce risk of serious side effects. Administer IV doses very slowly, over 2 min.
Therapeutic actions
  • Verapamil inhibits entry of calcium ions into arterial smooth muscle cells as well as the myocytes and conducting tissue. These actions lead to reversal and preventions of coronary artery spasm, reduction in afterload through peripheral vasodilatation and reduction in ventricular rate in patients with chronic atrial flutter or fibrillation and reduction in the occurrence of paroxysmal supraventricular tachycardia. Verapamil reduces BP, relieves angina and slows AV conduction.
Indications
  • Angina pectoris due to coronary artery spasm (Prinzmetal’s variant angina)
  • Effort-associated angina
  • Chronic stable angina
  • Unstable, crescendo, preinfarction angina
  • Essential hypertension
  • Parenteral: Treatment of supraventricular tachyarrhythmias
  • Parenteral: Temporary control of rapid ventricular rate in atrial flutter or atrial fibrillation
Adverse effects
  • Bradycardia, CHF, MI, AV block, worsening heart failure, transient asystole, hypotension, pulmonary and peripheral edema, nausea. Constipation, fatigue, hypotension, dizziness, headache, palpitation, flushing, nausea, rashes, alopecia, hyperprolactinaemia, increased LFT and arthralgia.
  • Potentially Fatal: Heart block and cardiac failure in patients with preexisting cardiac disease. Hepatotoxicity.
Contraindications
  • Cardiogenic shock, severe bradycardia, severe left ventricular dysfunction, uncompensated heart failure, hypotension (systolic pressure <90 mm Hg), porphyria. Patients with atrial flutter or atrial fibrillation and an accessory bypass tract (e.g., Wolff-Parkinson-White, Lown-Ganong-Levine syndromes). 2nd or 3rd degree AV block (unless pacemaker is fitted).
Nursing considerations
Assessment
  • History: Allergy to verapamil; sick sinus syndrome; heart block; IHSS; cardiogenic shock, severe CHF; hypotension; impaired hepatic or renal function; pregnancy, lactation
  • Physical: Skin color, edema; orientation, reflexes; P, BP, baseline ECG, peripheral perfusion, auscultation; R, adventitious sounds; liver evaluation, normal output; LFTs, renal function tests, urinalysis
Interventions
  • WARNING: Monitor patient carefully (BP, cardiac rhythm, and output) while drug is being titrated to therapeutic dose. Dosage may be increased more rapidly in hospitalized patients under close supervision.
  •  Ensure that patient swallows SR tablets whole; patient should not cut, crush, or chew them.
  • Monitor BP very carefully with concurrent doses of antihypertensives.
  • Monitor cardiac rhythm regularly during stabilization of dosage and periodically during long-term therapy.
  • Administer SR form in the morning with food to decrease GI upset.
  • Protect IV solution from light.
  • Monitor patients with renal or hepatic impairment carefully for possible drug accumulation and adverse reactions.
Teaching points
  • Take sustained-release form in the morning with food; swallow it whole, do not cut, crush, or chew it. Do not drink grapefruit juice while using this drug.
  • You may experience these side effects: Nausea, vomiting (eat frequent small meals); headache (adjust lighting, noise, and temperature; request medication); dizziness, sleepiness (avoid driving or operating dangerous equipment); emotional depression (reversible); constipation (request aid).
  • Report irregular heartbeat, shortness of breath, swelling of the hands or feet, pronounced dizziness, nausea, constipation.